G250 stuck adjustment knob

[Zung]

Well, pretty chrome is scratchable too, and I'm way more p****d when I scratch mine's, whereas a plastic cover for the G250 is only $20 after which it's like new...

Back to topic: I'd go easy on the vinegar.

 

[halocline]

OMG! You don't have a G250!! :shocked2:
Yeah, I know it's not shiny chrome like the 109. But there have been just a couple of technological advancements in the past 30 years. Have you converted any of your 109's to 156's? Then I rest my case -- having a balanced low pressure seat with a lighter spring was an improvement.
And venturi? Compare the flow diagrams for a 109/156 with a G250. Venturi was a good thing, too!

I have both a G250 (have had several) and several converted 109s. Eventually the 109s have all won out in terms of how often I use them. I agree that the balanced poppet is (IMO) an improvement in performance, especially in terms of holding a tune, and most of my 109s have the s wing poppet and new levers. But the added venturi assist in the G250 does nothing for me personally. (except aggravate dry mouth a bit) I couldn't care less about flow diagrams as a diver; I think it's interesting from an engineering perspective, but as a diver I really just want a comfortable natural feel to the reg, and I find the metal case more enjoyable in that regard. This is purely a preference, I'm not saying that one is 'better' than the other. I almost never use the G250.

I also prefer the converted pilots to the air 1s and D300s I have, I guess that makes me a metalhead of sorts.

 

[rsingler]

Not to fight with you, halo, but I'm not talking about Work of Breathing loops in Scuba Diving Magazine, but Pete Wolfinger's inhalation resistance graphs. I'd submit that venturi assist is a big deal, dry mouth or no. If I'm huffing and puffing trying to fight some cold water current, then my instantaneous inspiratory flow rate might reach 4 SCFM during part of each breath, even if my normal SAC is less than .6 SCFM. If I can have that come to me at less than 1" of suck instead of 1 1/2" or 2", then I'll last a lot longer. I'm an old guy.

I've gotta say, I dive my 109's for the pleasure of showing off. It's nice to be an old guy at depth with a beautiful reg that works perfectly in recreational conditions. It always generates some debate, and I can crack it at 1" just like everybody else's $700 set. But put me to work in cold water, and I'd honestly prefer to have some venturi assist. Actually, in those conditions I'm diving my metal orifice D400, where the inspiratory effort drops to 0.4" at high flows.

We're hijacking this guy's thread. Maybe we should start a new debate just for the fun of it.

 

[beanojones]

How would that matter? A poor service job coupled with inadequate user maintenance could produce that problem in short order (weeks).

This is why that know got slathered with goo when I used them. Still not as prone to getting jammed as the Apeks VIVA lever which can basically lock into place with grit after one dive in fine enough silt.

 

[mdax]

When I have regulator problems I can't figure out I take them to someone trained and experienced...like Dan.

 

[redacted]

When I have regulator problems I can't figure out I take them to someone trained and experienced...like Dan.

Is Dan in the back of the cave with you?

 

[PfcAJ]

When I have regulator problems I can't figure out I take them to someone trained and experienced...like Dan.

Ive got a stack of em to bring to ol' DP next time I'm in High Springs. Taking a year off has done a number on my reg stash.

 

[Luis H]

Not to fight with you, halo, but I'm not talking about Work of Breathing loops in Scuba Diving Magazine, but Pete Wolfinger's inhalation resistance graphs. I'd submit that venturi assist is a big deal, dry mouth or no. If I'm huffing and puffing trying to fight some cold water current, then my instantaneous inspiratory flow rate might reach 4 SCFM during part of each breath, even if my normal SAC is less than .6 SCFM. If I can have that come to me at less than 1" of suck instead of 1 1/2" or 2", then I'll last a lot longer. I'm an old guy.

I've gotta say, I dive my 109's for the pleasure of showing off. It's nice to be an old guy at depth with a beautiful reg that works perfectly in recreational conditions. It always generates some debate, and I can crack it at 1" just like everybody else's $700 set. But put me to work in cold water, and I'd honestly prefer to have some venturi assist. Actually, in those conditions I'm diving my metal orifice D400, where the inspiratory effort drops to 0.4" at high flows.

We're hijacking this guy's thread. Maybe we should start a new debate just for the fun of it.

The 109 has venturi flow assistance. Actually all regulators (that I am familiar with) from the 70's and newer has some form of venturi flow assistance (some better than others). The only regulators that I deal with that do not has any venturi would be a Broxton era double hose (well actually the new Aqua Lung Mistral has very poor flow also).

Every 109 (or 156) that I have adjusted will crack at 0.8 inWC to 1.2 inWC (unless there is something wrong), but they inhalation vacuum will drop with any significant flow. Many will approach 0 inWC during flow test (occasionally they will go positive). That demonstrate a very respectable venturi flow assist.


Note: venturi flow assistance was first introduced by Emile Gagnan with the introduction of the first single stage double hose regulators. That was in the mid 1950's. The first regulator with venturi assist was the US Divers Over-pressure DX, quickly followed by the Stream-Air DW, and finally by the Mistral DW. The first two stage regulator to introduce venturi flow assist was the DA Aqua Master.

The earlier regulators (in the late 40's)were all two stage regulators, but they didn't have any venturi flow assist. If you dive one of those you can tell a huge difference.


Sorry to temporary hijack the thread...

 

[halocline]

The 109 has venturi flow assistance.

Exactly, it's just that the G250 has a vane to adjust it, and I suspect the geometry is such that with the vane in maximum assist, there's more than in the 109. But to me this feels un-natural, like air is being pushed into my mouth.

I've never noticed much difference in cracking effort between my 109s and G250s.

 

[PfcAJ]

The hot cold thing was the trick, its starting to loosen up. Thanks guys.